An embodiment of the invention relates to a method and apparatus for medical imaging and in particular to a method and apparatus for the classification of pixels in medical imaging. An embodiment of the invention relates to Contrast Medium-enhanced Mammography (CMM) by X-rays and the injection of a contrast medium.
Mammography is medical imaging intended particularly for the detection of tumors by examination of successive images taken to reveal the variation with time of impregnation of the contrast medium and its gradual disappearance. In mammography the contrast medium tends to attenuate X-rays significantly more than a non-impregnated tissue, and thus reveals particularly vascularised zones such as tumors. But the variation of contrast within the breast itself provides an important indication about whether or not tumors are present, by the rate at which this contrast appears and disappears.
At present, contrast medium-enhanced mammography is practiced within the context of MRI, a technique that comprises making molecules composing the examined organ vibrate. Within this context, the variation of contrast in the breast is displayed on the screen in the form of a sequence of images that the practitioner interprets based on experience, as revealing or not revealing the presence of a tumor.
Marx et al., “Contrast-enhanced digital mammography (CEDM): phantom experiment and first clinical results”, Proc. SPIE—International Soc. for Optical Engineering, vol. 4682, pp. 174-181, 2002, proposes to produce maps representing the distribution of some parameters in the breast. These parameters are measurements illustrating some kinetic aspects of contrast variation obtained from a sequence of X-ray images.
However, the diagnosis work to be done by the practitioner is still considerable.